The present invention relates to a putter-type golf club, and more specifically to a golf putter head.
Putting is often considered the most difficult part of the game of golf. When putting, the golf ball must be hit with a precise amount of force and in a precise direction. If not, the golf ball either will fail to reach the cup (i.e. hole) or it will miss the cup on one side or the other. Various attempts have been made to design putters and in particular putter heads which facilitate imparting the precise amount of force and direction to a golf ball to successfully complete a putt.
Most putter head designs are variations of either a blade type putter head or a mallet type putter head; both these types of putter heads are affected by parameters which can cause mishit and misdirected putts. The mallet-style putter has a relatively large, solid head that usually is semi-circular in shape when viewed from above, while the blade-style putter has a relatively narrow or blade-like head. Each type of putter includes a generally flat strike face for hitting the golf ball, usually set at a loft of about 5xc2x0 or less. Accuracy of the putt is dependent on where the strike face impacts the ball, as well as on the orientation of the strike face at impact. Among the parameters that can cause mishit puts are the width of the putter head face (FW), the length of the putter head (L), and the location of the putter head center of gravity (CG).
The face or front of the putter head is that portion of the head which actually makes direct contact with the golf ball. Most blade type and mallet type putter heads employ a face that is usually as wide or almost as wide as the widest portion of the head. Typically, blade type putter heads have face widths greater than 4 inches while mallet type heads have face widths greater than 3 inches. The length of the putter head is defined as the distance from the face to the back the putter head. The width of the putter head face and the length of the putter head are factors in successful putting in that they affect the pre-putt alignment of the putter head, the impacting of the golf ball on the xe2x80x9csweet spotxe2x80x9d of the putter face, and the location of the putter head center of gravity.
Pre-putt alignment of a blade or mallet type putter head normally is accomplished by determining a line of sight to the cup and then positioning the putter head behind the golf ball on that line of sight with the putter head face perpendicular to the line of sight. If the face of the putter head is not perpendicular to the line of sight when the putter head impacts the ball, misdirection of the putt will occur. As the length of the putt increases, even a small misalignment results in a missed putt. The alignment procedure could be simplified and improved by reducing putter head face width (FW) so as to allow only a small facial area to impact the golf ball, increasing putter head length (L), and putting an alignment stripe on the top of the putter head. In order to ensure that the putter head conforms to USGA rules, however, the face width must be wider than the head is long. The USGA rules relating to putters are incorporated herein by reference.
Because USGA rules limit the reduction of the face width to head length ratio, many putters are designed so that the sweet spot size is increased. Impacting the golf ball on the sweet spot of the putter face involves determining the location of this spot and then consistently hitting the ball there. The sweet spot can be defined as a small area (typically having a width no greater than one half inch) on the face of a putter head that can impact a golf ball with the required force utilizing the shortest possible putter stroke to successfully complete a putt. The sweet spot is normally located such that a vertical middle plane will bisect the sweet spot, the putter head face, and pass through the putter head center of gravity. For example, the sweet spot on a blade type putter head face four and one half inches wide would normally be centered on the putter head face two and a quarter inches from either end of the blade. Error in the form of weak and ineffectual putts is introduced when the golf ball does not impact the sweet spot, and this error becomes greater as the distance between the sweet spot and the point of impact increases. Also, impacting the golf ball at or near the end of a mallet or blade type putter head can cause putter head twist resulting in misdirected putts.
The location of the center of gravity of the putter head is also a factor in successful putting in that increasing the distance between the center of gravity and the face of the putter head allows the golfer to take a shorter more controlled backswing of the putter head resulting in a higher percentage of positive contact with the golf ball. For a putter head of uniform density, this distance will increase as the length of the putter head is increased.
In recent years, golf club technology has evolved rapidly, with many different modifications having been made to the general structure of golf club heads, including putter heads. For example, golf club heads have been designed with back face undercuts having inserted weights, with holographic inserts on the trailing edge bevel, with cut-out sections extending through both the sole and crown of the club head, and with a strike face having two planar surfaces, one being offset from the other. Other more recent design initiatives include the placement of a xe2x80x9chorseshoexe2x80x9d as an aft-mass object so that the majority of the weight of the putter head is in the rear of the club, rather than the face and body, thus altering the club""s weight distribution. This design is embodied in the new Titleist(copyright) Futura putter. Putter heads have also been designed with recessed back cavities. One of the most popular types of these putters are the Callaway xe2x80x9c2-Ballxe2x80x9d putters, which are described in U.S. Pat. No. 6,471,600 to Tang, et al. and U.S. Pat. No. 6,506,125 to Helmstetter, et al.
Thus, while numerous modifications have been made to golf club heads in recent years, there is a continued need in the art to improve functionality, look, and feel of putters while conforming to USGA requirements.
According to an aspect of the present invention a golf putter head includes: a body having a face portion, a sole portion and an aft-mass portion, the body being at least partially made from a first material; and a cap made from a second material, the second material having a lower density than the first material; wherein the body and cap define a void and wherein the center of gravity of the golf putter head is within the void.
According to another aspect of the present invention, a golf putter head includes: a body having a face portion, a sole portion and an aft-mass portion, the body being at least partially made from a body material, the face portion being greater in width than the aft-mass portion, but less in width than the width of the putter head at its widest point; a cap made from a light material, the light material having a lower density than the first material; and at least one aft-mass weight being made from a heavy material having a higher density than the body material; wherein the body and cap define a void and wherein the center of gravity of the golf putter head is within the void.